Computer scientists have isolated the movements of Olympic swimmers and divers through a cutting-edge technique that reveals their motions above and below the water's surface.

he work, conducted by Manhattan Mocap, LLC, together with New York University's Movement Laboratory and The New York Times, analyzes Dana Vollmer, who won three gold medals at the 2012 Summer Olympics in London, as well as Abby Johnston, who won a silver medal in synchronized diving, and Nicholas McCrory, a bronze medalist in synchronized diving.

The research team, headed by Chris Bregler, a professor in NYU's Courant Institute of Mathematical Sciences, followed these athletes during their training in pools across the United States this spring and deployed ground-breaking motion-capture techniques to unveil their movement above and under the water's surface.

Of particular note is the team's creation of a system, AquaCap (TM), which captures underwater motion. It was used to display Vollmer's butterfly stroke and underwater dolphin kick, breaking down the technique the swimmer used to win the gold medal in the 100-meter butterfly in world-record time. Through a comparison of motions, the video illustrates how closely Vollmer's kick resembles that of a dolphin swimming through the water.

Subsequent work analyzed Johnston and McCrory, showing through previously unseen angles their summersaults from 3- and 10-meter diving boards and marking another technical breakthrough in motion capture.